Safety devices, such as harnesses, waist belts or other similar fall prevention devices are a requirement for persons working in elevated positions in accordance with government regulations and a desire for safety. In addition, sports enthusiasts such as rock and wall climbers may also wear these safety devices during such endeavors.
Generally, the person puts on the harness or waist belt which is then releasably secured to a lanyard. The lanyard, usually a three foot length of rope or webbed fabric, e.g., polyester, nylon, etc. with connection members at each end, is then releasably connected to a rope grab device or some other fixed holding member. In the case of a rope grab, the rope grab is in turn, attached to a independent safety line connected to an elevated structure. The safety line typically extends downward to a lower elevation or to the ground. In the event the person falls, the rope grab device, due to the initial jerk, will automatically activate and grab the safety line and thereby suspend the individual at or near the activation position.
The suspended person can then be rescued by a ladder, "cherry picker" or by utilizing a self-actuated lowering device to lower himself/herself to a lower elevation. Lowering devices are disclosed in the patent literature and some are commercially available to enable a suspended individual to initiate a safely controlled descent down a rope after the suspended person secures such a lowering device to the safety line. One such device is produced by Descent Control Inc., Fort Smith, Ark. as Model No. DT2&3 under the trademark SKY GENIE. The SKY GENIE device permits a person suspended from a safety rope to attach the device to the rope and descend down the rope. Other examples of such lowering devices are found in U.S. Pat. Nos. 3,220,511 and 3,250,515.
In my co-pending United States patent application, Ser. No. 466,898, filed on Jan. 18, 1990, entitled "Fall Prevention and Lowering System and Methods of Use", there is disclosed and claimed a safety system utilizing a robe grab and a lowering device for protecting persons located at elevated positions from falling while enabling such persons to safely descend.
As will be appreciated by those skilled in the art, during a fall from an elevated structure, due to a person's weight and the force of gravity, the tension on the lanyard increases almost instantaneously when the rope grab device is actuated to suspend the person from the safety line. The gravitational force is transmitted to and felt by the person connected to the lanyard. This gravitational force may stun the individual, or even knock the individual unconscious, thereby hampering the individual's ability to safely descend down the safety line with a lowering device, or otherwise aid in an assisted descent. More importantly, the shock of the gravitational force may cause the person to sustain an injury to the neck, head, back, e.g., whiplash.
To protect persons from or minimize the effects of such a shock, shock absorbing lanyards are commercially available. Such lanyards typically include a shock absorbing mechanism housed within a casing connected between the ends of the lanyard. One particularly effective shock absorbing lanyard is sold by Descent Control, Inc., of Fort Smith, AR, under the trademark SOFT LANDING. This lanyard relies on the frictional threading of a folded length of the lanyard in a serpentine path through a buckle (when webbed fabric is used) or through frictional ferrules (when a rope lanyard is used) to decrease the perceived shock. As tension is applied to the lanyard, the folded portion of the lanyard stored in the area above/alongside the buckle or frictional ferrules, passes therethrough. The frictional force imposed on the lanyard material by the buckle or frictional ferrules abates the gravitational shock felt when a person begins to fall.
To function properly, the conventional SOFT LANDING lanyard requires the folded portion of the lanyard frictionally passing through the buckle or frictional ferrules, to be properly folded, stored and protected from tampering, soiling or accidental activation. These concerns have typically been met by the use of some sort of a resilient cover. Although such covers over the shock absorber may provide some protection, it does not permit a user to readily inspect the shock absorber prior to use without potentially interfering with the later functioning of the device. Moreover, such covers do not provide a visual indication of whether the shock absorber had previously been tampered with or actuated.
Accordingly, a need exists for a visually inspectable shock absorbing lanyard to be used in any type of suspension or safety system.